/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.functions.hive.util;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

import java.util.List;

import static org.apache.flink.util.Preconditions.checkArgument;

/**
 * Test array in generic UDF.
 */
public class TestGenericUDFArray extends GenericUDF {

	@Override
	public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
		checkArgument(arguments.length == 1);
		checkArgument(arguments[0].getTypeName().equals("array<int>"));
		return PrimitiveObjectInspectorFactory.javaIntObjectInspector;
	}

	@Override
	public Object evaluate(DeferredObject[] arguments) throws HiveException {
		List<Integer> list = (List<Integer>) arguments[0].get();
		return list.stream().reduce((i1, i2) -> i1 + i2).orElse(0);
	}

	@Override
	public String getDisplayString(String[] children) {
		return "TestGenericUDFArray";
	}
}
